test_sum.py

def test_empty():
    assert sum([]) == 0

def test_positive():
    assert sum([1, 2, 3]) == 6

def test_negative():
    assert sum([-1, -2]) == -3

def test_floats():
    assert abs(sum([0.1, 0.2]) - 0.3) < 0000.1

def test_start():
    assert sum([1, 2], 10) == 13

def test_no_params():
    try:
        sum()
    except TypeError:
        pass

def test_bad_params():
    try:
        sum(["a", "b"])
    except TypeError:
        pass